Facile synthesis of 1,9-diacyldipyrromethanes
The present invention provides a method of making a metal complex. The method comprises the steps of: (a) acylating a dipyrromethane or a 1-monoacyldipyrromethane to form a mixed reaction product comprising a 1,9-diacyidipyrromethane; (b) combining the reaction product with a compound of the formula R 2 MX 2 in the presence of a base, where R is alkyl or aryl, M is Sn, Si, Ge, or Pb (preferably Sn), and X is halo, OAc, acac, or OTf, to form a product comprising a metal complex of the formula DMR 2 in the mixed reaction product, wherein D is a 1,9-diacyldipyrromethane; and then (c) separating the metal complex from the mixed reaction product. The method may be utilized for the convenient synthesis and separation of 1,9-diacyldipyrromethanes. Metal complex intermediates useful in such methods are also described.
1. A method of making a metal complex, comprising the steps of:
(a) acylating a dipyrromethane or a 1-monoacyldipyrromethane to form a mixed reaction product comprising a 1,9-diacyldipyrromethane;
(b) combining said mixed reaction product with a compound of the formula R 2 MX 2 in the presence of a base, where R is alkyl or aryl, M is Sn, Si, Ge, or Pb, and X is halo, OAc, acac or OTf, to form a metal complex of the formula DMR 2 in said mixed reaction product, wherein D is a 1,9-diacyldipyrromethane; and then
(c) separating said metal complex from said mixed reaction product.
2. The method of claim 1 , wherein said acylating step (a) is carried out by reacting said dipyrromethane or 1-monoacyldipyrromethane with a compound of the formula R 3 COX, where R 3 is alkyl or aryl and X is halo, to form said mixed reaction product comprising a 1,9-diacyldipyrromethane acylated at the 1 and 9 positions with R 3 CO—.
3. The method of claim 1 , wherein said acylating step (a) is carried out by reacting said dipyrromethane or 1-monoacyldipyrromethane with an acid chloride and a Grignard reagent to form said mixed reaction product comprising a 1,9-diacyldipyrromethane.
4. The method of claim 1 , wherein said acylating step (a) is carried out by reacting said dipyrromethane or 1-monoacyldipyrromethane with an active ester to form said mixed reaction product comprising a 1,9-diacyldipyrromethane.
5. The method of claim 1 , wherein said acylating step (a) is carried out by reacting said dipyrromethane or 1-monoacyldipyrromethane with a Vilsmeier reagent to form said mixed reaction product comprising a 1,9-diacyldipyrromethane.
6. The method of claim 1 , wherein said base is selected from the group consisting of triethylamine, tributylamine, N,N-diisopropylamine, DBU, DBN, and 2,6,-di-tert-butylpyridine.
7. The method of claim 1 , wherein M is Sn.
8. The method of claim 1 , wherein said acylating step (a) is carried out with a dipyrromethane which is thereby acylated at the 1 and 9 position to produce said 1,9-diacyldipyrromethane.
9. The method of claim 1 , wherein said acylating step (a) is carried out with a 1-monoacyldipyrromethane which is acylated at the 9 position to produce said 1,9-diacyldipyrromethane.
10. The method of claim 1 , wherein said compound of the formula R 2 MX 2 is immobilized on a solid support.
11. The method of claim 1 , further comprising the step of:
(d) treating said metal complex with an acid to produce a 1,9-diacyldipyrromethane.
12. The method of claim 11 , wherein said acid is selected from the group consisting of trifluoroacetic acid, trichloroacetic acid, acetic acid, HCl, p-toluene sulfonic acid.
13. The method of claim 1 , further comprising the steps of:
(d) reducing said metal complex with a reducing agent to form a diol from said 1,9-diacyldipyrromethane; and then
(e) condensing said diol with a dipyrromethane to form a porphyrin ring compound therefrom.
14. The method of claim 13 , wherein said reducing agent is NaBH 4 .
15. The method of claim 1 , wherein said dipyrromethane is substituted at the 5 position with a substituent selected from the group consisting of H, alkyl, and aryl.
16. The method of claim 1 , wherein said dipyrromethane is substituted at the 5 position with a substituent selected from the group consisting of dipyrromethane, porphyrin, dipyrrin, and diacyldipyrromethane.
17. A method of making a metal complex, comprising:
reacting a 1,9-diacyldipyrromethane with a compound of the formula R 2 MX 2 in the presence of a base, where R is alkyl or aryl, M is Sn, Si, Ge or Pb, and X is halo, OAc, acac or OTf, to form a metal complex of the general formula DMR 2 , wherein D is said 1,9-diacyldipyrromethane.
18. The method of claim 17 , wherein said base is selected from the group consisting of triethylamine, tributylamine, N,N-diisopropylamine, DBU, DBN, and 2,6,-di-tert-butylpyridine.
19. The method of claim 17 , wherein M is Sn.
20. A metal complex of the general formula DMR 2 , wherein D is a 1,9-diacyldipyrromethane, M is Sn, Si, Ge, or Pb, and R is alkyl or aryl.
21. The metal complex of claim 20 , wherein M is Sn.
22. The metal complex of claim 20 , wherein said dipyrromethane is substituted at the 5 position with a substituent selected from the group consisting of H, alkyl, and aryl.
23. The metal complex of claim 20 , wherein said dipyrromethane is substituted at the 5 position with a substituent selected from the group consisting of dipyrromethane, porphyrin, dipyrrin, and diacyldipyrromethane.